The present inventor previously developed a speech-controlled phonetic typewriter or display device using a two-tier approach, the latter being disclosed in U.S. Pat. No. 4,435,617 Griggs, which is incorporated herein by reference thereto.
The previously patented typewriter or display device represented an advance over devices of the prior art, and provided for satisfactory transcription when presented with carefully enunciated speech. However, as speech becomes faster, more and more elements are dropped from, distorted in or abbreviated in such speech as it tries to keep pace with the thoughts of the speaker. As a result, too many phonemes are missing or are altered, and facile word identification and transcription by the use of phonemes is made difficult or impossible.
The present inventor has discovered that the typewriter or display device of previous U.S. Pat. No. 4,435,617 provides satisfactory transcription with carefully enunciated speech or until the speech becomes too fast. Once speech becomes too fast or is not carefully enunciated, words must be extracted, if at all, according to features of speech that are more gross and less precise than in the typewriter or display device previously disclosed and claimed.
The following patents are considered generally relevant as background art relative to the presently disclosed invention: U.S. Pat. Nos. 3,440,617: 3,558,820; 3,646,576; 3,798,372; 3,808,371; 3,846,586; 3,869,576; 4,039,754; 4,060,694; 4,121,058; 4,156,868; 4,181,821; 4,272,813; 4,388,495; 4,412,098; 4,415,767; 4,653,086; and 4,675,840.